Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
In Europe, the breeding population is estimated to number 3,720,000-6,500,000 pairs, which equates to 7,440,000-13,000,000 mature individuals (BirdLife International 2015). Europe forms 85% of the global range, so a very preliminary estimate of the global population size is 8,750,000-15,300,000 mature individuals, although further validation of this estimate is needed.
The population is suspected to be in decline in part owing to competition from H. polyglotta in the west of the range (del Hoyo et al. 2006). In Europe, trends between 1980 and 2013 show that populations have undergone a moderate decline (EBCC 2015).
This species inhabits tall-grown woods of oak (Quercus), birch (Betula), beech (Fagus sylvatica), alder (Alnus) and other deciduous trees, but it is also found in larger parks and gardens, and in stands of young pines (Pinus) if mixed with broadleaf trees. It favours open forest, or dense woods with intermixed glades and undergrowth. Breeding occurs from the end of May to July and clutches are four to five. The nest is a strong cup of grasses, plant stems, moss and soft twigs, often covered with pieces of birch bark, lichens, flowers and similar, partly attached with cobwebs and lined with fine fibres, roots, fur and similar soft material. It is placed in the fork of a tree branch. The diet is mostly insects and other invertebrates but in the summer it also takes fruits and berries. The species is migratory, wintering in Africa, south of the equator (Svensson 2006).
Decreases in the west and south-west of it range may be in part due to competition from Hippolais polyglotta, which has spread north and east to become marginally sympatric (Svensson 2006).
Conservation Actions Underway
CMS Appendix II. Bern Convention Appendix II. There are currently no known conservation measures for this species within Europe.
Conservation Actions Proposed
No conservation measures are currently needed for this species within its European range.
Text account compilers
Ekstrom, J., Ashpole, J, Butchart, S.
BirdLife International (2019) Species factsheet: Hippolais icterina. Downloaded from http://www.birdlife.org on 14/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 14/12/2019.